Apparatus and method for making concrete roadways



Sept- 9, 1941- I R. w. BAILY 2,255,342

APPARATUS AND METHOD FOR 4MAKING CONCRETE ROADWAYS Filed Feb. l5, 1930 Patented Sept. 9, 1941 APPARATUS AND METHOD FR MAKING CONCRETE ROADWAYS Robert w. muy, Philadelphia, Pa. IApplication February 15, 1930, Serial No. 428,747

-14 Claims.

My invention relates to apparatus and method for striking off or leveling the surface of aconcrete or similar type of roadway and vibrating the latter to cause the concrete to become exceedingly dense and homogeneous and rid it of entrapped air and water.

It is one object of this invention to provide a novel method and means for striking olf the surface of a concrete roadway through the use of a strike-off board or screed and intensively vibrating the concrete by mechanism carried by the screed so that the concrete becomes a dense practically fluid mass readily flowing to places of least resistance and causing the elimination of air and water entrapped in the concrete.

Referring to the accompanying drawing:

Figure 1 is a transverse vertical section of one form of my novel apparatus, the section taken on the line I-I on Figure 2 and parts being broken away;

Figure 2 is aplan view of the apparatus;

Figure 3 is an elevation of one ofthe vibrators, the view being at right angles to the viewof the vibrator shown directly above it in Figure 1.

In the drawingfthe numeral I designates a screed extending from one side of the roadway to the other and resting at its ends on the side forms 2, the screed having on its lower side the guides 3 which engage with the outer faces of.

vthe forms'. The guides 3 may be omitted, if

desired.

The face-plate 4 is hinged near its lower edgel to the forward part of the screed. I show two hinges 5 which are each composed of two members, one marked 6 being secured to the upper face of the screed and the other marked 1 being secured to the rear face of the face-plate. The two members of each hinge are connected pivotally together 'by a hinge pin 8. vThe members of each hinge have a series of transverse holes 9 to receive a pin 9 for locking the face-plate at different selected angular relations with the screed I. The face-plate is braced in any selected position by the two-part braces III, one part marked II being pivoted at one end to the therewith, and at 4b in dotted lines -at about an angle of therewith. It will be readily understood that the 'bolts 9? and I5 can be withdrawn and reinserted in suitable holes 9 and I4 to hold the face-plate at any selected possible angle with the screed.

The screed I has on its upper side any suitable vibrating mechanism.v By way of example, I have shown the mechanism now to be described. The screed has attached toits upper face a suitable number of standards I6 supporting the rotary shaft I1 arranged transversely of the screed. The shaft may be driven by any `suitable power, such as a gas engine, gasoline engine, electric motor or other prime mover which may be mounted on the screed or elsewhere. I showthe pulley I8 on the-shaft I1 merelyto indicate that power of some kind is to be applied to rotate the shaft. The shaft has at each standard a crank I9 to which a T-shaped weight 20 is connected. Preferably the standards have two members 2I between which the cranks turn. The middle leg 22 of each weight is connected to its respective crank while the ends of the cylindrical head of the weight is guided vertically by the slots 23 in the membersV The important features of my invention are that the screed I always remains in contact with the concrete or any top finish thereon, as broken stone', and that the vibration produced by the weight 20 shall havehigh frequency or impulses in excess of 900 perminute and preferably exceeding 2500 frequencies or impulses per minute.

I My invention does not tamp or pound the concrete, but imparts to it very rapid intensive vi,

bration causing what mightotherwise be a stiff harsh mass to become practically a fluid and rear side of the face-plate near its upper edge,

and the other part marked I2 being pivoted at one end to the bracket I3 on the rear edge of the screed. The remaining ends of the parts II and I2 I4 arranged longitudinally thereof to receive the bolts I5 for making the braces rigid.

Figure 1 shows in full lines the face-plate at about an angle of 135 with the screed I, and at'la in dotted lines at overlap each other and have the holes about an angle of 55 hence to flow easily. The concrete is violently agitated by the weights or whatever vibratory means is used, causing the air entrapped in the concrete to rise to the surface and escape, leaving a dense and homogeneous mass. I do away with the necessity for providing means for the escape of entrapped air, such as grids, slotsfsmall openings, transmitting platforms and the like, because the entrapped air escapes from thev concrete before the face-plate 4 passes beyond it.

The face-plate 4 receives considerable vibration not only operating vertically but also horizontally. The face-plate imparts to the concrete below the necessary vibration to cause it to now to position and to b e freed of entrapped air, so that the concrete beneath the screed is free from airand excess water.

The described apparatus may be moved backward or forward as described by the handles 24 carried at the outer ends of the handle bars 25, but any other suitable means may be used for moving the same.

When the concrete is stiff and hard, it is preferable to have the face-plate inclined forwardly, as shown in full lines in Figure 2 but where the concrete is wet or'quite plastic, the face plate may be moved to the position shown in dotted lines at 4a or even further to the right or the rear as shown at 4b, so that the concretei .is directly pushed or partially lifted asthe apparatus is moved forwardly. In order to keep the concrete between the form 2, the end plates 35 of the apparatus have the wings 26 which are inclined inwardly and rearwardly.

The intensity of the described vibration may be varied by the substitution of weights of different mass, using cranks of different throws, or changing the number of revolutions of the cranks per minute. Y

2l designatesthe concrete in front of the face-plate 4 while 28 denotes the dense concrete roadway slab after it has been vibrated into a dense homogeneous mass without air or excess water.

It is obvious that my method may be used with Portland cement concrete, bituminous concrete or any other pavement-making materials to which it is adapted.

I claim as my invention:

l. A method for treating plastic material to compact the same, expel air therefrom and bring the surface thereof to approximately a predetermined surface contour, comprising advancing thereover a screed for engaging and striking oi the part of the body of the material projecting above the elevation of the desired contour, and vibrating the same in planes approximately parallel to the forward direction of the travel of the screed.

2. In a Vibratory apparatus for treating plastic material, a screed, means for maintaining the screed at approximately a predetermined elevation for movement along the material for reducing it to a desired contour, means for imparting to the screed vibrations in planes approximately parallel with the forward direction of the travel of the screed.

3. A method for treating plastic material to compact the same, expel air therefrom and bring the surface thereof to approximately a predetermined surface contour, comprising advancing thereover a screed for engaging and striking off the part of the body of the material projecting abofe the elevation of the desired contour, and Vibrating the same so that the major effect of the impulses shallI be" in planes approximately parallel to the forward" direction of the travel of the screed.

4. In a concrete working machine, the combination of a shoe adapted for horizontal reciprocatory movement and provided with a front plate adapted for supporting engagement with a substantial mass of concrete against which the shoe is advanced, said shoe having a nose projecting in front of said plate, and means for vibrating said shoe and front plate.

5. In a concrete working machine, the combination of a shoe provided with a front plate adapted for supporting engagement with a substantial mass of concrete against which the shoe is advanced, shoe having a nose projecting in front of said plate, and means for vibrating said shoe and front plate.

6. In a concrete working machine, the combination of a screed having a nose at its' front edge, and a front plate extending upwardly from said nose, and means for vibrating said shoe in planes approximately parallel with the forward direction of its travel.

7. 'I'he method of constructing a slab of a material comprising depositing the material on a supporting medium, propelling lforwardly that portion of the material projecting above a. predetermined `elevation and internally vibrating said material being propelled by vibrations imparted in directions, some of which are approximately parallel to the forward direction of travel and restraining said projecting material within the desired lateral boundaries of the material.

8. Vibratory apparatus comprising a structure to be vibrated, said structure having an axis approximately in the direction of its greatest dimension, said apparatus being adapted to travel laterally to said axis at a predetermined elevation and in contact with a material to be vibrated, a vibrator mechanism secured to said structure and including a transverse rotatable shaft, with a weight off center thereon to vibrate the structure when the shaft is rotated, means imparting rotation to the shaft whereby some components of the forces exerted on the structure by the weight project forwardly in planes perpendicular to said axis of the structure.

9. In an apparatus for treating concrete having a vibrating member, a -plurality of spaced vibrators on the member, each vibrator including a crank, a connecting rod leg connected offcenter with such crank and a weight operated by said connecting rod and ieg, means for guiding the weight, and means for rotating the cranks for actuating the weights for imparting vibrations through said apparatus to material to be vibrated. l

10. A method for treating in forms, a material which is plastic when vibrated to compact the same, expel air therefrom and bring the surface thereof yto approximately a predetermined contour and to conserve surplus material, comprising progressively striking olf the part of the material projecting above the elevation of the desired surface contour between the forms, restraining said material projecting above the desired contour from passing over the forms and propelling said surplus .material forwardly and vibrating the material before and below the location of the striking ofi in directions, some of which are parallel to said forms.

11. Vibratory apparatus comprising a structure to be vibrated, said structure `having an axis Y approximately in the direction of its greatest dimension, said apparatus being adapted to travel laterally to said axis at a predetermined elevation and in contact with a material to be vibrated, a vibrator mechanism secured to said structure and including a transverse rotatable shaft, with a weight off center thereon to vibrate the structure when the shaft is rotated. means imparting rotation to the shaft whereby some components of the forces exerted on the structure by the weight project forwardly in planes perpendicular 12.. Apparatus for spreading and compacting paving materials including supporting means screed for imparting thereto vibrations in planes approximately parallel to the direction of travel of the screed.

14. The method of treating a material by advaricing a screed thereover for severing that portion of the materal'lying above a predetermined elevation, `and imparting surface vibrations to the material lying below the struck-off level in forwardly and-downwardly directions.

ROBERT W. BAILY.

front face member and said flat face member 'connected by a curved portion, means for supporting the screed and m'eans supported on the 

